Flex 3 & Air 2: Automatically detect when files on a directory are updated - apache-flex

Question

A crazy idea just dropped from the sky and hit me in the head xD. I was wondering if it is possible to make and App capable of listening when the user "adds" new files to a directory.
Example:
The User opens up our Application.
The user adds new files on the desktop (using the Microsoft Explorer).
Our application automatically detects that new files have been added and executes a function or whatever.
Sound interesting right?
Maybe, this could be done using a programming language like Visual Basic and open the executable with the NativeProcess api and listen for an stdOut event... (:
Anyone got and idea to share with us? :)
Thanks
Lombardi

Answer 1

AIR can handle this natively...
the FileSystemList class fires an event directoryChange whenever a file in the watched directory changes.
You can even use it to watch for drives being mounted (I think Christian Cantrell showed that one off)

Answer 2

Ok, I think I'm getting closer, check out this solution! :)
private var CheckDelay:Timer = new Timer(5000, 0);
private function InitApp():void
{
CheckDelay.addEventListener(TimerEvent.Timer, CheckForNewFiles, false, 0, true);
CheckDelay.start();
}
private function CheckForNewFiles(event:TimerEvent):void
{
var FS:FileStream = new FileStream();
var Buffer:File = File.applicationStorageDirectory.resolvePath("FilesBuffer.cmd");
FS.open(Buffer, FileMode.Write);
FS.writeUTFBytes("cd " + File.desktopDirectory.nativePath + "\r\n" +
"dir /on /b > " + File.applicationStorageDirectory.resolvePath("FileList.txt").nativePath);
FS.close();
var Process:NativeProcess = new NativeProcess();
var NPI:NativeProcessStartupInfo = NativeProcessStartupInfo(); // What a large name! xD
NPI.executable = Buffer;
Process.start(NPI);
Process..addEventListener(NativeProcessExitEvent.EXIT, ReadFileList, false, 0, true);
}
private function ReadFileList(event:Event):void
{
var FS:FileStream = new FileStream();
var Buffer:File = File.applicationStorageDirectory.resolvePath("FilesBuffer.cmd");
FS.open(Buffer, FileMode.Read);
var FileData:String = FS.readUTFBytes(FS.bytesAvailable);
FS.close();
var FileArray:Array = FileData.split("\r\n");
var TempArray:ArrayCollection = new ArrayColletion();
var TempFile:File;
for(var i:int = 0;i<FileArray.length;i++){
TempFile = new File(FileArray[i]);
TempArray.addItem(TempFile);
}
}
At the end we got an Array (TempArray) that we could use on a datagrid (for example) with colums like: "extension, File Name, FilePath, etc.."
The files are updated every 5 seconds.
And, why we use all that code instead of a simple "File.getDirectoryListing()"? Because we are updating our application every 5 seconds, if why use getDirectoryListing(), our application will take much more RAM and also, the cmd command is much faster... :)
If you have a better idea, please share it with us! Thank you! :D

Answer 3

1 excellent solution for Windows: use Visual Studio, build the .net app found here http://msdn.microsoft.com/en-us/library/system.io.filesystemwatcher.aspx
In Adobe AIR use the native process to listen for change events dispatched by .net